Climbing structure



FIG. 1—is a front first side perspective view of a climbing structure showing my design;

FIG. 2—is a top view thereof;

FIG. 3—is a front elevational view thereof;

FIG. 4—is a second side elevational view thereof;

FIG. 5—is a first side elevational view thereof; and,

FIG. 6—is a rear elevational view thereof. 

I claim the ornamental design for a climbing structure, as shown. 